On 20 May 2017 02:36, "Brent Meeker" <meeke...@verizon.net> wrote:
On 5/19/2017 5:30 PM, David Nyman wrote: On 19 May 2017 at 21:00, Brent Meeker <meeke...@verizon.net> wrote: > > > On 5/19/2017 8:45 AM, John Clark wrote: > > On Thu, May 18, 2017 spudboy100 via Everything List < > everything-list@googlegroups.com> wrote: > > > >> So which is the Boss, John, Mathematics, somehow at the 'base; of the >> universe, or is physics the top dog from the 1st split second? > > > > One of > > René > Magritte's > most famous paintings is called "Ceci n'est pas une pipe", in English > that means " > this is not a pipe". > > http://i3.kym-cdn.com/entries/icons/facebook/000/022/133/the > -treachery-of-images-this-is-not-a-pipe-1948(2).jpg > > This is how Magritte explained his painting: > > * " The famous pipe. How people reproached me for it! And yet, could you > stuff my pipe? No, it's just a representation, is it not? So if I had > written on my picture 'This is a pipe', I'd have been lying! " * > > Mathematics is a representation of something it is not the thing itself. > Physics is the thing itself. > > > Bruno's a Platonist. That means that conscious thoughts are what we have > immediate access to and the physical world is an inference from perceptions > (which are thoughts). We take the physical world to be real insofar as our > inference has point-of-view-invariance so that others agree with us about > perceptions. Bruno observes that consciousness is associated with and > dependent on brains, which are part of the inferred physical world. He > supposes this is because brains realize certain computations and he > hypothesizes that conscious thoughts correspond to certain computations. > But computation is an abstraction; given Church-Turing it exists in the > sense that arithmetic exists. So among all possible computations, there > must be the computations that constitute our conscious thoughts and the > inferences of a physical world to which those thoughts seem to refer... but > not really. It's the "not really" where I part company with his > speculations. That inferred physical world is just as computed as Max > Tegmark's and is just as necessary for consciousness as brains and skulls > and planets are. So, for me, the question is whether something is gained > by this reification of computation. Bruno says it provides the relation > between mind and body. But that's more a promise than a fact. It provides > some classification of thoughts of an ideal thinker who doesn't even think > about anything except arithmetic. > I really think you continue to miss something crucial here. The thinker (which is admittedly a toy version at this stage) isn't merely thinking "about" arithmetic. It's thinking about (or more accurately perceiving) *arithmetical truth*. So what's the difference? Well, 2+2=4 is a tautology of arithmetic; IOW it merely expresses something that is formally necessitated in the very definition of the terms. What does it then add to say that it is true that 2+2=4? Well, we test the truth of this assertion by perceiving that it corresponds with the (perceptual) facts. For example, as you often like to say, we can simply see that two objects plus two more objects is indeed equal to four objects. Now, this idea of truth as correspondence with the facts has no direct parallel in physics, computation per se, or any other purely formally-defined procedural specification. ?? For these latter, it is sufficient that there is such a procedure and that it is followed. There is no further entailment of truth or falsity that can have any bearing on the outcome. On the other hand the notion of truth parallels precisely that characteristic of perception fixed on by many thinkers on the subject, perhaps most notably Descartes who correctly intuited that the one thing in his experience that could not coherently be doubted was that it was true. What he thought he could not doubt was that he was thinking. Bertrand Russell noted that he could have doubted there was a subject doing the thinking. Thank you so much for these helpful emendations. "He thought he could not doubt that it was true that he was thinking." Any better? Then Russell's contribution would have been to note (with suitable substitution of pronouns) that he could have doubted there was a he doing the thinking. Even more illuminating? Perhaps you would remind me what precision such painstaking discriminations are supposed to add at this point. To be unambiguous, that primary truth is not of course proof against delusion; as Descarte also correctly inferred, his true experience could nonetheless have been imposed on him by a malignant demon. In that case, however, it would still of course have been the canvas on which the delusory perceptions were truthfully painted. But what's the relevance of such a notion of simple arithmetical truths to perceptions such as our own? Well, if thought and perception, by assumption in the computationalist framework, are to be considered a consequence of computation, which itself devolves upon arithmetical relations, then the truths of perception must in some relevant sense be generalisations of the truths of arithmetic. Yes, the usual, "If this theory is going to work out then it must be that ...." As of course is the case with reasoning in any other theory. I might as well have said that if thought and perception were to be considered in the end simply physical then they would necessarily have to be generalisations of physics. As Bruno says, perception becomes a view from the "inside" of arithmetic, where that elusive internal space (which we seek in vain in extrinsically-completed models such as physics tout court) is equated with the truths, as distinct from the formal procedures, of arithmetic. The strength of the logical models that Bruno utilises in the machine interviews is then that they can be characterised in this sense as "accessing truths". The only truths he shows they can access are those provable in PA - which is because he defines "accessible" as "provable". But you forget that the necessary generalisation has not yet been fully accomplished. The task at this point is to show that in principle it could be accomplished with the tools at hand. It's also the case that we similarly cannot extrapolate from neuroscience to a theory of perception. The crucial difference however is that the goal of a completed neuroscience will have been accomplished by the explication of perceptual *behaviour*, not its putative truth, which is not in any sense a neurocognitive category. As you often opine, many will be satisfied that all possibility of explanation will have been exhausted at this point. However, their purely extrinsic formulation is in the relevant sense "incomplete" in this regard. Their completion in that same sense is to be found in the conjunction of an extrinsic formulation with an intrinsic (reflexive) logic that is comprehensible only in terms of what the subject thus modelled perceives to be true, i.e to correspond with its perceptually-available "facts". The consequence is then that consciousness is equated in this view with whatever is perceptually true, in the first instance, for a given subject. But we have no reason to suppose that there is a unique physics in this computational plethora. You are much too quick here. We have no reason (contradictions or other refutations) to suppose that there isn't and at least promising signs that there could be. This is ordinarily sufficient encouragement to engage one's interest in where this line of enquiry might lead next. I take it that you however are not so encouraged. So a coherent set of "perceptually available facts" is just a wish, a promisory note on the bank of everythingism. So you'd rather bank elsewhere, as of course is your privilege. But at the same time you're also a little like the Greenspan of everythingism, anxious to warn us of irrational exuberance. Nonetheless, promissory notes aren't always unworthy of their paper. You haven't done enough yet in my view to discourage a modest further investment in this general direction. David Brent Now, toy model or not, ISTM that there is surely something in the foregoing that offers certain relevant conceptual footholds that are unavailable in alternative schemas. It's also something that can in principle be examined and tested rigorously even though it is at present largely neglected and at a very early stage of development. At least it seems to offer a way of avoiding the equally unpalatable polarities I mentioned before - of brute identity theory on the one hand, or the fruitless search for some "internal" state of matter on the other. Either of these alternatives has struck me for a long time as falling into the category of "not even wrong". David > "Body" isn't in the theory except as a promise that it must be there if > the theory is to explain everything. > > Brent > "Plato says we should seek reality in our thoughts rather than watching > shadows on the cave wall. But all human advancement has come from studying > those shadows." > --- Sean Carroll > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to everything-list+unsubscr...@googlegroups.com. > To post to this group, send email to everything-list@googlegroups.com. > Visit this group at https://groups.google.com/group/everything-list. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
